US3019411A - Echo detection with delayed read out - Google Patents

Echo detection with delayed read out Download PDF

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Publication number
US3019411A
US3019411A US710291A US71029158A US3019411A US 3019411 A US3019411 A US 3019411A US 710291 A US710291 A US 710291A US 71029158 A US71029158 A US 71029158A US 3019411 A US3019411 A US 3019411A
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Prior art keywords
echo
recording
output
pulse
erase
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Expired - Lifetime
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US710291A
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English (en)
Inventor
Haslett Roy William George
Hopkin Peter Roy
Benning Norman Henry
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Kelvin Hughes Ltd
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Kelvin Hughes Ltd
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/88—Sonar systems specially adapted for specific applications
    • G01S15/96—Sonar systems specially adapted for specific applications for locating fish
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/04—Display arrangements

Definitions

  • the present invention relates to echo-ranging and the like, that is to say systems in which pulses or bursts of waves are emitted from a transmitter, some of the wave energy is reflected as echo signals from objects in their path back to a receiver and the received echo signals are displayed or recorded upon a time base. Examples of such systems are echo-sounding in water, flaw detection in solid bodies to be tested, and radar.
  • the invention is an improvement in or modification of the invention claimed in patent application Ser. No. 560,820, filed January 23, 1956.
  • echo-ranging or like equipment for displaying or recording echo signals from a predetermined range of distances from a wave transmitter
  • the equipment comprising a display or recording device, means for triggering a time base of the display (such as a cathode ray tube) or recording device under the control of an echo signal from a region at the further limit of or beyond the said range, means for delaying received echo signals from within the said range by a time equal to or greater than twice the time of travel of the wave between the extremity of the said range nearer the transmitter and the said region, and means for applying the delayed signals to the display or recording device.
  • the said region may be the sea bottom and the invention is of special value when the predetermined range is near the sea bottom. Since, when using that invention, a bottom echo serves to control the triggering of the time-base, and since the delay of the received signals applied to the tube is fixed, the position on the screen of the cathode ray tube of the bottom echo remains fixed.
  • the said region may be the rear surface of the body under test, that is the surface opposite to that into which the waves are injected and through which they are received after reflection.
  • the said region may for example be the coastline when the equipment is being operated from aircraft or at sea.
  • the pulses may be emitted at regular or irregular intervals and the intervals may be wholly random throughout or may be in recurrent, like groups, the intervals Within each group varying in a random or regular manner.
  • the time base is arranged, between successive transmissions, to execute a plurality of sweeps and to display or record the same echo signals, suitably delayed, during each of these sweeps.
  • the time base is arranged, between successive transmissions, to execute a plurality of sweeps and to display or record the same echo signals, suitably delayed, during each of these sweeps.
  • Such a magnetic recorder requires in addition to the recording and reproducing heads, an erase head by means of which recorded signals are erased and the recorder put in condition to record a fresh set of signals. It is necessary to space the recording and reproducing heads sufficiently to avoid undesired coupling between these heads, and it is physically impossible to make the erase and recording heads co-incident in position owing to their size, and since the recorded matter must be erased before new matter is recorded.
  • an erase and bias oscillator generates an oscillation which is applied on the one hand to the erase head to erase recorded matter and on the other hand to the recording head to bias this head into its operative condition.
  • the erasure and the commencement of recording occur simultaneously.
  • the spacing between the erase and recording heads along the recording track which may be on a drum, disk or endless tape, the erased track will take a time I to reach the recording head, where t is the linear speed of the track divided by the linear distance along the track between the erase and recording heads. This time may in practice be about 5 mseconds.
  • the recording medium which will for convenience in description be considered to be a drum, is arranged to make several rotations between the reception of echoes from successive transmitted pulses.
  • oscillation is applied to the erase and recording heads simultaneously for a period of say 25 mseconds in each transmitted pulse recurrence period.
  • This double recording therefore takes place for a time t in each pulse recurrenceperiod.
  • a further portion of track corresponding to a time t is wasted because the recording head is rendered inoperative at a time when this portion of track which has been erased has still to pass the recording head.
  • the total time wasted is 10 mseconds. which represents hali the total recording space. -The number of possible repetitions of the echo signals in each pulse recurrence period is thus reduced.
  • an echo ranging or like apparatus wherein received echo signals are delayed in time before they are displayed or recorded, wherein the echo signals are delayed with the aid of recording means including a recording medium co-operating with and moving relatively to a recording head, a reproducing head and an erase head, the erase head being adapted to erase previously recorded matter, and wherein the recording and erase heads are rendered operative by means of switching signals of such relative phase that the erase head is rendered operative at a time before the recording head is rendered operative, approximately equal to the time of travel of the medium from the erase to the recording head or to the time between traversals of a given point on the medium by the erase and recording heads.
  • the recording apparatus is conveniently a magnetic recording apparatus it is not necessarily so. It can be of any kind such that signals can be recorded and Moreover the erase and bias" reproduced from a moving medium and erased.
  • the recording medium may be stationary and the heads may move.
  • FIG. 1 is ., a block circuit diagram of one embodiment of the invention
  • FIG. 2 is a block circuit. diagram of a modification of the embodiment in FIG. 1, and
  • FIG. 3 shows waveforms present atvarious points in the circuits of FIGS. 1 and 2.
  • each of the waveforms is designated by a small letterand this letter appears in FIGS. 1 and 2 at the point where, that waveform occurs.
  • the transmitter portion of a transmitter-receiver. 10, which is not shown in detail in FIG. 1. but which may be as described in the earlier specificationhereinbefore referred to, generates pulses a assumed to have a.recurrence period of 500 ms. and converts theseto. thebroader pulsesb.
  • the trailing edges of the pulses b serve to trigger a transmissionrpulsegenerator which generates a burst of'oscillations of suitable frequency at each triggering, and these bursts are applied to adransmitting transducer.
  • Thereceiving portion of the component ltthas a transducer which receives echoes and produces an echo signal output 0.
  • This waveform comprises a break-through 11 of the transmittedpulse, an echo 12 from the sea bottom and an echo; 13 from fish.
  • the bottom echo is selected by; an amplitude gate 14. capable vof lt assing Qnly -signaIseXceeding a predeterv minedamplitude and the output d of this gate is fed to a multivibratorlfij and-triggers .itto generate the waveform e.
  • the multivibr awr 15. is so constituted that when triggered it generates a negativegoingedge 16 and then remains unresponsive to any further triggering until a predetermined time-has elapsed, in this example assumed to.be,475 ms., when it produces the positive-going edge 1']. Itisthen in a condition to respond to afurther triggering pulse of the waveform d.
  • the circuit comprises a recording means in this example assumed to be a magnetic drum 18 rotated at auniform speed in the directionof the arrow and having a recording head 19, an erase head 2% and a reproducing head 21.
  • the waveform c is applied from the receiver in,10.to an amplifier 22 Whose output is coupled to the recording head19.
  • recording of these signals takes place (apart from relatively inetficient recording tobe referred to hereinafter) only when, at the same time, a,high frequency bias is applied to the head.
  • This bias is generated by an oscillation generator 23 generating. acontinuous oscillation coupled to a bias gate 24.
  • This gate is arranged to be opened to permit the bias'to pass .tothe recording head 19 when the waveform e from themultivibrator is positive.
  • the bias applied to the recording head 19 is as shown at f. mentioned that the breakthrough pulse 11 in FIG. 3 c isassu-med to be the first pulse and it is for this reason that the high frequency oscillation is shown in FIG. 3 f ascontinuing until the bottom echo 12 is received.
  • a further multivibrator 25 is provided and this is also triggered by the waveform d from the amplitude gate 14 and generates thewaveform g.
  • the multivibrator 25 when triggered, the multivibrator 25 generates a negative-going edge 26 andremains unresponsive to any further triggering until a predetermined time later when the positive-going edge 27 occurs. In this example the time is 475-t ms.
  • the waveform g is applied to an erase gate 28 to open this gate when the waveform g is positive to allow erase oscillations to be fed from the oscillation generator 23 to the erase head 20 as shown by waveform h.
  • the reproducing head 21 picks up the recorded signals It should be I 4.- with a time delay (assumed in this example to be 10 ms.) determined by the speed of the drum 18 and the distance between the heads 19 and 21.
  • a time delay (assumed in this example to be 10 ms.) determined by the speed of the drum 18 and the distance between the heads 19 and 21.
  • the recorded fish echo signals 13 are reproduced 10 ms. after they have been recorded and are followed by the bottom echo signal 12 which has been recorded at the recording head 19immediately before the negative-going edge 16 of the waveform e switched off the recording bias to that head and is reproduced 10 ms. later at thereproducing head.
  • the fish and bottom echo signals are reproduced once in every revolution of the drum, that is to say with a recurrence period of 20 ms.
  • resulting signals from the reproducing head 21, which are represented diagrammatically by the waveform j in FIGURE 3, are amplified at 29 and fed to adisp
  • a time base 31 for the device 30 isswitched by the waveform e from the multivibrator IS and, when triggered, generates a seriesof sweeps, as shown in FIG. 3 k, until stopped by the positive going edge of the waveform 6. On each of these sweeps one cycle of signals reproduced by the reproducing head 21 is displayed, as indicated by the relationship in time between the wave-v forms and k of FIG. 3.
  • repeating scan may also be carried out at a higher rate than with the apparatus described in the earlier specification.
  • a gate is providedbetweenthe, receiverofechq signals and the recording head and means. are provided for applying a gating signal to open the gate only at times when recording is required.
  • the gating signal is arranged to be in step with the switching, of the, bias oscillation on to the recording head and may be derived,
  • FIG. 2 Acircuit by which this feature of the inventiomcan. beput into practice is shown in FIG. 2.- Thisufigure. alsoshows a modified arrangement for gating, the,biasing and erasing oscillations. Likecomponents inFIGS .,1 and 2 have the same reference.
  • the multiviorator 25 generatesthewavefornrg, as in FIG. 1, and thiscontrols the erase gate 28.
  • a multivibrator 32 is arrangedto be triggered by the positive-goingedge 27 of the waveform g and, when so triggered, to generate a negative-going pulse of dUIZI-r tion t as shown in FIG. 3 I. This pulseis-added in an adder 33 to the waveform g to produce thewaveform e which is fed to the bias gate 24 and to trigger thetirne base31.
  • the waveform e is also fed to a record gate 34 -to open this gate when the waveformis positive.
  • the use of the multivibrator 32 generating the waveform I and adding this waveform to the waveformgto The produce the waveform e has the advantage over the arrangement of FIG. 1 that any instability in the multivibrators produces less change in the duration of the negative-going pulse of waveform e.
  • Echo ranging apparatus comprising receiver means for receiving echo signals, signal display means, a delay device comprising recording, reproducing and erase heads coupled between said receiver means and said display means, said device comprising a recording medium mounted for movement relative to and co-operating with said recording, reproducing and erase heads, and actuating means rendering said erase head operative prior to actuation of said recording head.
  • actuating means comprise a source of oscillations, separate gating means coupled between said source and said erase and recording heads, two gating signal generating means and means coupling each of said gating signal generating means to a difierent one of said gating means.
  • Echo ranging apparatus comprising receiver means for receiving echo signals, signal display means, signal recording means comprising a recording head coupled to said receiver means, a reproducing head coupled to said display means, an erase head, and a recording medium mounted in co-operating relation with and movable recurrently relatively to said heads to traverse a given point on said medium a plurality of times, means for actuating said erase head recurrently after a plurality of traversals of a point on said medium past said erase head, a gating device coupled between said receiver means and said recording head, gating signal generating means coupled to said gating device and opening said gate recurrently for a time not exceeding that between two successive ones of said traversals, whereby the relative switching times of said erase and recording heads are such that said erase head is actuated prior to the actuating of said recording head.
  • Echo ranging apparatus comprising receiver means for receiving echo signals, signal display means, a recording medium, a recording head coupled to said receiver means and arranged to record echo signals on said medium, a reproducing head coupled to said display means and arranged to pick up signals from said medium, an erase head for erasing signals recorded on said medium, means for producing relative motion between said medium and said heads whereby a point on said medium travels successively past said erase head, said recording head, and said reproducing head, first actuating means for rendering said recording head operative, second actuating means for rendering said erase head operative, and control means for operating said second actuating means at a time before said first actuating means.
  • Apparatus as claimed in claim 4 in which the recording medium is a magnetic recording medium, the apparatus including a source of oscillations coupled by said first actuating means to said recording head and by said second actuating means to said erase head, and said control means comprising a separate operating signal generator for each of said actuating means.
  • Apparatus as claimed in claim 5 including amplitude gating means coupled between said receiver means in said control means to provide an initiating signal for each operating signal generator.
  • an erase head for erasing signals recorded on the recording medium, means for producing relative motion between said medium and said heads whereby a point on said medium travels successively past said erase head, said recording head, and said reproducing head, an oscillation generator, first actuating means for connecting the oscillation generator to the erase head, second actuating means for connecting the oscillation generator to the recording head to apply a recording bias thereto, and control means for operating said first actuating means and, at a predetermined time interval thereafter, operating said second actuating means and said gating means.
US710291A 1957-01-24 1958-01-21 Echo detection with delayed read out Expired - Lifetime US3019411A (en)

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Application Number Priority Date Filing Date Title
GB2640/57A GB839131A (en) 1957-01-24 1957-01-24 Improvements in and relating to echo-sounding and the like

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US3019411A true US3019411A (en) 1962-01-30

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US (1) US3019411A (fr)
BE (1) BE544683A (fr)
DE (1) DE1193685B (fr)
FR (2) FR1140572A (fr)
GB (3) GB785001A (fr)
NL (3) NL224215A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3296580A (en) * 1963-11-19 1967-01-03 Smith & Sons Ltd S Echo sounding apparatus
US5695149A (en) * 1993-12-11 1997-12-09 Beiersdorf Aktiengesellschaft Carrier-roller winder

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB811440A (en) * 1957-12-05 1959-04-08 Marconi Wireless Telegraph Co Improvements in or relating to subaqueous echo sounders
US3030608A (en) * 1959-10-12 1962-04-17 Gen Railway Signal Co Detector for high-speed traffic
US3110007A (en) * 1959-10-14 1963-11-05 Gen Signal Corp Ultrasonic vehicle detector
NL137773C (fr) * 1960-03-21
GB1104094A (en) * 1963-11-29 1968-02-21 Plessey Uk Ltd Improvements in or relating to echo sounders
DE1257641B (de) * 1964-05-05 1967-12-28 Beteiligungs & Patentverw Gmbh Echolotverfahren fuer die Tiefseefischerei
DE1516632B1 (de) * 1966-05-05 1970-01-15 Electroacustic Gmbh Echolotgerät mit einstellbarer Tiefenbereichsanzeige und mit bodengebundener Tiefenbereichsanzeige, wobei die Tiefenbereichsanzeige als stehendes Bild auf dem Schirm einer Kathodenstrahlr¦hre als Anzeigeorgan erscheinen
DE1516639B1 (de) * 1966-12-21 1970-03-19 Electroacustic Gmbh Bodengebundene Anzeige mit Hilfe eines vor dem Aufzeichnungsimpuls ausgesandten Ausloeseimpulses,dessen Frequenz gegenueber der des Aufzeichnungsimpulses verschieden ist und bei der eine Trennung von Aufzeichnungsimpuls und Ausloeseimpuls auf der Empfangsseite durch Bandfilter erfolgt
DE2924176C2 (de) * 1979-06-15 1982-11-18 Fried. Krupp Gmbh, 4300 Essen Verfahren zur Darstellung von Rückstrahlortungssignalen zur Ausübung des Verfahrens
CN108474843B (zh) * 2016-01-29 2022-06-28 松下知识产权经营株式会社 距离测量装置

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2418136A (en) * 1943-11-10 1947-04-01 Bell Telephone Labor Inc Acoustic range finder
US2729803A (en) * 1949-12-22 1956-01-03 Raytheon Mfg Co Recording depth sounder

Family Cites Families (2)

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Publication number Priority date Publication date Assignee Title
DE954221C (de) * 1952-06-18 1956-12-13 Atlas Werke Ag Verfahren und Vorrichtung zum Aufzeichnen von ueber dem Grund stehenden Fischschwaermen od. dgl. Objekten durch Echolotung
DE1012222B (de) * 1954-12-13 1957-07-11 Electroacustic Gmbh Impulsgetastetes Echolotgeraet

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2418136A (en) * 1943-11-10 1947-04-01 Bell Telephone Labor Inc Acoustic range finder
US2729803A (en) * 1949-12-22 1956-01-03 Raytheon Mfg Co Recording depth sounder

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3296580A (en) * 1963-11-19 1967-01-03 Smith & Sons Ltd S Echo sounding apparatus
US5695149A (en) * 1993-12-11 1997-12-09 Beiersdorf Aktiengesellschaft Carrier-roller winder

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Publication number Publication date
NL203812A (fr)
FR1140572A (fr) 1957-07-29
DE1193685B (de) 1965-05-26
NL110770C (fr)
BE544683A (fr)
NL224215A (fr)
GB785001A (en) 1957-10-23
GB839132A (en) 1960-06-29
GB839131A (en) 1960-06-29
FR73126E (fr) 1960-09-23

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